// Emacs style mode select	 -*- C++ -*-
//-----------------------------------------------------------------------------
//
// $Id:$
//
// Copyright (C) 1993-1996 by id Software, Inc.
//
// This source is available for distribution and/or modification
// only under the terms of the DOOM Source Code License as
// published by id Software. All rights reserved.
//
// The source is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// FITNESS FOR A PARTICULAR PURPOSE. See the DOOM Source Code License
// for more details.
//
// $Log:$
//
// DESCRIPTION:
//		Gamma correction LUT stuff.
//		Functions to draw patches (by post) directly to screen.
//		Functions to blit a block to the screen.
//
//-----------------------------------------------------------------------------


static const char
rcsid[] = "$Id: v_video.c,v 1.5 1997/02/03 22:45:13 b1 Exp $";


#include "i_system.h"
#include "r_local.h"

#include "doomdef.h"
#include "doomdata.h"

#include "m_bbox.h"
#include "m_swap.h"

#include "v_video.h"


// Each screen is [SCREENWIDTH*SCREENHEIGHT];
byte*							screens[5];

int								dirtybox[4];



// Now where did these came from?
byte gammatable[5][256] =
{
    {   1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,
        17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,
        33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,
        49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,
        65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80,
        81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,
        97,98,99,100,101,102,103,104,105,106,107,108,109,110,111,112,
        113,114,115,116,117,118,119,120,121,122,123,124,125,126,127,128,
        128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143,
        144,145,146,147,148,149,150,151,152,153,154,155,156,157,158,159,
        160,161,162,163,164,165,166,167,168,169,170,171,172,173,174,175,
        176,177,178,179,180,181,182,183,184,185,186,187,188,189,190,191,
        192,193,194,195,196,197,198,199,200,201,202,203,204,205,206,207,
        208,209,210,211,212,213,214,215,216,217,218,219,220,221,222,223,
        224,225,226,227,228,229,230,231,232,233,234,235,236,237,238,239,
        240,241,242,243,244,245,246,247,248,249,250,251,252,253,254,255
    },

    {   2,4,5,7,8,10,11,12,14,15,16,18,19,20,21,23,24,25,26,27,29,30,31,
        32,33,34,36,37,38,39,40,41,42,44,45,46,47,48,49,50,51,52,54,55,
        56,57,58,59,60,61,62,63,64,65,66,67,69,70,71,72,73,74,75,76,77,
        78,79,80,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,97,98,
        99,100,101,102,103,104,105,106,107,108,109,110,111,112,113,114,
        115,116,117,118,119,120,121,122,123,124,125,126,127,128,129,129,
        130,131,132,133,134,135,136,137,138,139,140,141,142,143,144,145,
        146,147,148,148,149,150,151,152,153,154,155,156,157,158,159,160,
        161,162,163,163,164,165,166,167,168,169,170,171,172,173,174,175,
        175,176,177,178,179,180,181,182,183,184,185,186,186,187,188,189,
        190,191,192,193,194,195,196,196,197,198,199,200,201,202,203,204,
        205,205,206,207,208,209,210,211,212,213,214,214,215,216,217,218,
        219,220,221,222,222,223,224,225,226,227,228,229,230,230,231,232,
        233,234,235,236,237,237,238,239,240,241,242,243,244,245,245,246,
        247,248,249,250,251,252,252,253,254,255
    },

    {   4,7,9,11,13,15,17,19,21,22,24,26,27,29,30,32,33,35,36,38,39,40,42,
        43,45,46,47,48,50,51,52,54,55,56,57,59,60,61,62,63,65,66,67,68,69,
        70,72,73,74,75,76,77,78,79,80,82,83,84,85,86,87,88,89,90,91,92,93,
        94,95,96,97,98,100,101,102,103,104,105,106,107,108,109,110,111,112,
        113,114,114,115,116,117,118,119,120,121,122,123,124,125,126,127,128,
        129,130,131,132,133,133,134,135,136,137,138,139,140,141,142,143,144,
        144,145,146,147,148,149,150,151,152,153,153,154,155,156,157,158,159,
        160,160,161,162,163,164,165,166,166,167,168,169,170,171,172,172,173,
        174,175,176,177,178,178,179,180,181,182,183,183,184,185,186,187,188,
        188,189,190,191,192,193,193,194,195,196,197,197,198,199,200,201,201,
        202,203,204,205,206,206,207,208,209,210,210,211,212,213,213,214,215,
        216,217,217,218,219,220,221,221,222,223,224,224,225,226,227,228,228,
        229,230,231,231,232,233,234,235,235,236,237,238,238,239,240,241,241,
        242,243,244,244,245,246,247,247,248,249,250,251,251,252,253,254,254,
        255
    },

    {   8,12,16,19,22,24,27,29,31,34,36,38,40,41,43,45,47,49,50,52,53,55,
        57,58,60,61,63,64,65,67,68,70,71,72,74,75,76,77,79,80,81,82,84,85,
        86,87,88,90,91,92,93,94,95,96,98,99,100,101,102,103,104,105,106,107,
        108,109,110,111,112,113,114,115,116,117,118,119,120,121,122,123,124,
        125,126,127,128,129,130,131,132,133,134,135,135,136,137,138,139,140,
        141,142,143,143,144,145,146,147,148,149,150,150,151,152,153,154,155,
        155,156,157,158,159,160,160,161,162,163,164,165,165,166,167,168,169,
        169,170,171,172,173,173,174,175,176,176,177,178,179,180,180,181,182,
        183,183,184,185,186,186,187,188,189,189,190,191,192,192,193,194,195,
        195,196,197,197,198,199,200,200,201,202,202,203,204,205,205,206,207,
        207,208,209,210,210,211,212,212,213,214,214,215,216,216,217,218,219,
        219,220,221,221,222,223,223,224,225,225,226,227,227,228,229,229,230,
        231,231,232,233,233,234,235,235,236,237,237,238,238,239,240,240,241,
        242,242,243,244,244,245,246,246,247,247,248,249,249,250,251,251,252,
        253,253,254,254,255
    },

    {   16,23,28,32,36,39,42,45,48,50,53,55,57,60,62,64,66,68,69,71,73,75,76,
        78,80,81,83,84,86,87,89,90,92,93,94,96,97,98,100,101,102,103,105,106,
        107,108,109,110,112,113,114,115,116,117,118,119,120,121,122,123,124,
        125,126,128,128,129,130,131,132,133,134,135,136,137,138,139,140,141,
        142,143,143,144,145,146,147,148,149,150,150,151,152,153,154,155,155,
        156,157,158,159,159,160,161,162,163,163,164,165,166,166,167,168,169,
        169,170,171,172,172,173,174,175,175,176,177,177,178,179,180,180,181,
        182,182,183,184,184,185,186,187,187,188,189,189,190,191,191,192,193,
        193,194,195,195,196,196,197,198,198,199,200,200,201,202,202,203,203,
        204,205,205,206,207,207,208,208,209,210,210,211,211,212,213,213,214,
        214,215,216,216,217,217,218,219,219,220,220,221,221,222,223,223,224,
        224,225,225,226,227,227,228,228,229,229,230,230,231,232,232,233,233,
        234,234,235,235,236,236,237,237,238,239,239,240,240,241,241,242,242,
        243,243,244,244,245,245,246,246,247,247,248,248,249,249,250,250,251,
        251,252,252,253,254,254,255,255
    }
};



int		usegamma;

//
// V_MarkRect
//
void
V_MarkRect
( int			x,
  int			y,
  int			width,
  int			height )
{
    M_AddToBox (dirtybox, x, y);
    M_AddToBox (dirtybox, x+width-1, y+height-1);
}


//
// V_CopyRect
//
void
V_CopyRect
( int			srcx,
  int			srcy,
  int			srcscrn,
  int			width,
  int			height,
  int			destx,
  int			desty,
  int			destscrn )
{
    byte*		src;
    byte*		dest;

#ifdef RANGECHECK
    if (srcx<0
            ||srcx+width >SCREENWIDTH
            || srcy<0
            || srcy+height>SCREENHEIGHT
            ||destx<0||destx+width >SCREENWIDTH
            || desty<0
            || desty+height>SCREENHEIGHT
            || (unsigned)srcscrn>4
            || (unsigned)destscrn>4)
    {
        I_Error ("Bad V_CopyRect");
    }
#endif
    V_MarkRect (destx, desty, width, height);

    src = screens[srcscrn]+SCREENWIDTH*srcy+srcx;
    dest = screens[destscrn]+SCREENWIDTH*desty+destx;

    for ( ; height>0 ; height--)
    {
        memcpy (dest, src, width);
        src += SCREENWIDTH;
        dest += SCREENWIDTH;
    }
}


//
// V_DrawPatch
// Masks a column based masked pic to the screen.
//
void
V_DrawPatch
( int			x,
  int			y,
  int			scrn,
  patch_t*		patch )
{

    int			count;
    int			col;
    column_t*	column;
    byte*		desttop;
    byte*		dest;
    byte*		source;
    int			w;

    y -= SHORT(patch->topoffset);
    x -= SHORT(patch->leftoffset);
#ifdef RANGECHECK
    if (x<0
            ||x+SHORT(patch->width) >SCREENWIDTH
            || y<0
            || y+SHORT(patch->height)>SCREENHEIGHT
            || (unsigned)scrn>4)
    {
        fprintf( stderr, "Patch at %d,%d exceeds LFB\n", x,y );
        // No I_Error abort - what is up with TNT.WAD?
        fprintf( stderr, "V_DrawPatch: bad patch (ignored)\n");
        return;
    }
#endif

    if (!scrn)
        V_MarkRect (x, y, SHORT(patch->width), SHORT(patch->height));

    col = 0;
    desttop = screens[scrn]+y*SCREENWIDTH+x;

    w = SHORT(patch->width);

    for ( ; col<w ; x++, col++, desttop++)
    {
        column = (column_t *)((byte *)patch + LONG(patch->columnofs[col]));

        // step through the posts in a column
        while (column->topdelta != 0xff )
        {
            source = (byte *)column + 3;
            dest = desttop + column->topdelta*SCREENWIDTH;
            count = column->length;

            while (count--)
            {
                *dest = *source++;
                dest += SCREENWIDTH;
            }
            column = (column_t *)(	(byte *)column + column->length
                                    + 4 );
        }
    }
}

//
// V_DrawPatchFlipped
// Masks a column based masked pic to the screen.
// Flips horizontally, e.g. to mirror face.
//
void
V_DrawPatchFlipped
( int			x,
  int			y,
  int			scrn,
  patch_t*		patch )
{

    int			count;
    int			col;
    column_t*	column;
    byte*		desttop;
    byte*		dest;
    byte*		source;
    int			w;

    y -= SHORT(patch->topoffset);
    x -= SHORT(patch->leftoffset);
#ifdef RANGECHECK
    if (x<0
            ||x+SHORT(patch->width) >SCREENWIDTH
            || y<0
            || y+SHORT(patch->height)>SCREENHEIGHT
            || (unsigned)scrn>4)
    {
        fprintf( stderr, "Patch origin %d,%d exceeds LFB\n", x,y );
        I_Error ("Bad V_DrawPatch in V_DrawPatchFlipped");
    }
#endif

    if (!scrn)
        V_MarkRect (x, y, SHORT(patch->width), SHORT(patch->height));

    col = 0;
    desttop = screens[scrn]+y*SCREENWIDTH+x;

    w = SHORT(patch->width);

    for ( ; col<w ; x++, col++, desttop++)
    {
        column = (column_t *)((byte *)patch + LONG(patch->columnofs[w-1-col]));

        // step through the posts in a column
        while (column->topdelta != 0xff )
        {
            source = (byte *)column + 3;
            dest = desttop + column->topdelta*SCREENWIDTH;
            count = column->length;

            while (count--)
            {
                *dest = *source++;
                dest += SCREENWIDTH;
            }
            column = (column_t *)(	(byte *)column + column->length
                                    + 4 );
        }
    }
}



//
// V_DrawPatchDirect
// Draws directly to the screen on the pc.
//
void
V_DrawPatchDirect
( int			x,
  int			y,
  int			scrn,
  patch_t*		patch )
{
    V_DrawPatch (x,y,scrn, patch);

    /*
    int			count;
    int			col;
    column_t*	column;
    byte*		desttop;
    byte*		dest;
    byte*		source;
    int			w;

    y -= SHORT(patch->topoffset);
    x -= SHORT(patch->leftoffset);

    #ifdef RANGECHECK
    if (x<0
    	||x+SHORT(patch->width) >SCREENWIDTH
    	|| y<0
    	|| y+SHORT(patch->height)>SCREENHEIGHT
    	|| (unsigned)scrn>4)
    {
    	I_Error ("Bad V_DrawPatchDirect");
    }
    #endif

    //	V_MarkRect (x, y, SHORT(patch->width), SHORT(patch->height));
    desttop = destscreen + y*SCREENWIDTH/4 + (x>>2);

    w = SHORT(patch->width);
    for ( col = 0 ; col<w ; col++)
    {
    	outp (SC_INDEX+1,1<<(x&3));
    	column = (column_t *)((byte *)patch + LONG(patch->columnofs[col]));

    	// step through the posts in a column

    	while (column->topdelta != 0xff )
    	{
    		source = (byte *)column + 3;
    		dest = desttop + column->topdelta*SCREENWIDTH/4;
    		count = column->length;

    		while (count--)
    		{
    			*dest = *source++;
    			dest += SCREENWIDTH/4;
    		}
    		column = (column_t *)(	(byte *)column + column->length
    								+ 4 );
    	}
    	if ( ((++x)&3) == 0 )
    		desttop++;	// go to next byte, not next plane
    }*/
}



//
// V_DrawBlock
// Draw a linear block of pixels into the view buffer.
//
void
V_DrawBlock
( int			x,
  int			y,
  int			scrn,
  int			width,
  int			height,
  byte*			src )
{
    byte*		dest;

#ifdef RANGECHECK
    if (x<0
            ||x+width >SCREENWIDTH
            || y<0
            || y+height>SCREENHEIGHT
            || (unsigned)scrn>4 )
    {
        I_Error ("Bad V_DrawBlock");
    }
#endif

    V_MarkRect (x, y, width, height);

    dest = screens[scrn] + y*SCREENWIDTH+x;

    while (height--)
    {
        memcpy (dest, src, width);
        src += width;
        dest += SCREENWIDTH;
    }
}



//
// V_GetBlock
// Gets a linear block of pixels from the view buffer.
//
void
V_GetBlock
( int			x,
  int			y,
  int			scrn,
  int			width,
  int			height,
  byte*			dest )
{
    byte*		src;

#ifdef RANGECHECK
    if (x<0
            ||x+width >SCREENWIDTH
            || y<0
            || y+height>SCREENHEIGHT
            || (unsigned)scrn>4 )
    {
        I_Error ("Bad V_DrawBlock");
    }
#endif

    src = screens[scrn] + y*SCREENWIDTH+x;

    while (height--)
    {
        memcpy (dest, src, width);
        src += SCREENWIDTH;
        dest += width;
    }
}




//
// V_Init
//
void V_Init (void)
{
    int			i;
    byte*		base;

    // stick these in low dos memory on PCs

    base = I_AllocLow (SCREENWIDTH*SCREENHEIGHT*4);

    for (i=0 ; i<4 ; i++)
        screens[i] = base + i*SCREENWIDTH*SCREENHEIGHT;
}
